[PATCH v4 3/3] PCI: qcom: add support for IPQ60xx PCIe controller

Baruch Siach
2021-12-27T06:46:15Z

From: Selvam Sathappan Periakaruppan <speriaka@codeaurora.org>

IPQ60xx series of SoCs have one port of PCIe gen 3. Add support for that
platform.

The code is based on downstream[1] Codeaurora kernel v5.4 (branch
win.linuxopenwrt.2.0).

Split out the DBI registers access part from .init into .post_init. DBI
registers are only accessible after phy_power_on().

[1] https://source.codeaurora.org/quic/qsdk/oss/kernel/linux-ipq-5.4/

Signed-off-by: Selvam Sathappan Periakaruppan <speriaka@codeaurora.org>
Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
---
v4:

* Rebase on v5.16-rc1

v3:
* Drop speed setup; rely on generic code (Rob Herring)

* Drop unused CLK_RATE macros (Bjorn Helgaas)

* Minor formatting fixes (Bjorn Helgaas)

* Add reference to downstream Codeaurora kernel tree (Bjorn Helgaas)

v2:
* Drop ATU configuration; rely on common code instead

* Use more common register macros

* Use bulk clk and reset APIs
---
drivers/pci/controller/dwc/pcie-designware.h | 1 +
drivers/pci/controller/dwc/pcie-qcom.c | 145 +++++++++++++++++++
2 files changed, 146 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index ea87809ee298..279c3778a13b 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -76,6 +76,7 @@

#define GEN3_RELATED_OFF 0x890
#define GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL BIT(0)
+#define GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS BIT(13)
#define GEN3_RELATED_OFF_GEN3_EQ_DISABLE BIT(16)
#define GEN3_RELATED_OFF_RATE_SHADOW_SEL_SHIFT 24
#define GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK GENMASK(25, 24)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 1c3d1116bb60..14f86c45a8d9 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -52,6 +52,10 @@
#define PCIE20_PARF_DBI_BASE_ADDR 0x168
#define PCIE20_PARF_SLV_ADDR_SPACE_SIZE 0x16C
#define PCIE20_PARF_MHI_CLOCK_RESET_CTRL 0x174
+#define AHB_CLK_EN BIT(0)
+#define MSTR_AXI_CLK_EN BIT(1)
+#define BYPASS BIT(4)
+
#define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT 0x178
#define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2 0x1A8
#define PCIE20_PARF_LTSSM 0x1B0
@@ -171,6 +175,11 @@ struct qcom_pcie_resources_2_7_0 {
struct clk *ref_clk_src;
};

+struct qcom_pcie_resources_2_9_0 {
+ struct clk_bulk_data clks[5];
+ struct reset_control *rst;
+};
+
union qcom_pcie_resources {
struct qcom_pcie_resources_1_0_0 v1_0_0;
struct qcom_pcie_resources_2_1_0 v2_1_0;
@@ -178,6 +187,7 @@ union qcom_pcie_resources {
struct qcom_pcie_resources_2_3_3 v2_3_3;
struct qcom_pcie_resources_2_4_0 v2_4_0;
struct qcom_pcie_resources_2_7_0 v2_7_0;
+ struct qcom_pcie_resources_2_9_0 v2_9_0;
};

struct qcom_pcie;
@@ -1297,6 +1307,127 @@ static void qcom_pcie_post_deinit_2_7_0(struct qcom_pcie *pcie)
clk_disable_unprepare(res->pipe_clk);
}

+static int qcom_pcie_get_resources_2_9_0(struct qcom_pcie *pcie)
+{
+ struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
+ struct dw_pcie *pci = pcie->pci;
+ struct device *dev = pci->dev;
+ int ret;
+
+ res->clks[0].id = "iface";
+ res->clks[1].id = "axi_m";
+ res->clks[2].id = "axi_s";
+ res->clks[3].id = "axi_bridge";
+ res->clks[4].id = "rchng";
+
+ ret = devm_clk_bulk_get(dev, ARRAY_SIZE(res->clks), res->clks);
+ if (ret < 0)
+ return ret;
+
+ res->rst = devm_reset_control_array_get_exclusive(dev);
+ if (IS_ERR(res->rst))
+ return PTR_ERR(res->rst);
+
+ return 0;
+}
+
+static void qcom_pcie_deinit_2_9_0(struct qcom_pcie *pcie)
+{
+ struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
+
+ clk_bulk_disable_unprepare(ARRAY_SIZE(res->clks), res->clks);
+}
+
+static int qcom_pcie_init_2_9_0(struct qcom_pcie *pcie)
+{
+ struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
+ struct device *dev = pcie->pci->dev;
+ int ret;
+
+ ret = reset_control_assert(res->rst);
+ if (ret) {
+ dev_err(dev, "reset assert failed (%d)\n", ret);
+ return ret;
+ }
+
+ usleep_range(2000, 2500);
+
+ ret = reset_control_deassert(res->rst);
+ if (ret) {
+ dev_err(dev, "reset deassert failed (%d)\n", ret);
+ return ret;
+ }
+
+ /*
+ * Don't have a way to see if the reset has completed.
+ * Wait for some time.
+ */
+ usleep_range(2000, 2500);
+
+ ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks);
+ if (ret)
+ goto err_reset;
+
+ return 0;
+
+ /*
+ * Not checking for failure, will anyway return
+ * the original failure in 'ret'.
+ */
+err_reset:
+ reset_control_assert(res->rst);
+
+ return ret;
+}
+
+static int qcom_pcie_post_init_2_9_0(struct qcom_pcie *pcie)
+{
+ struct dw_pcie *pci = pcie->pci;
+ u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+ u32 val;
+ int i;
+
+ writel(SLV_ADDR_SPACE_SZ,
+ pcie->parf + PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE);
+
+ val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
+ val &= ~BIT(0);
+ writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
+
+ writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
+
+ writel(DEVICE_TYPE_RC, pcie->parf + PCIE20_PARF_DEVICE_TYPE);
+ writel(BYPASS | MSTR_AXI_CLK_EN | AHB_CLK_EN,
+ pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
+ writel(GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS
+ | GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL,
+ pci->dbi_base + GEN3_RELATED_OFF);
+
+ writel(MST_WAKEUP_EN | SLV_WAKEUP_EN | MSTR_ACLK_CGC_DIS
+ | SLV_ACLK_CGC_DIS | CORE_CLK_CGC_DIS |
+ AUX_PWR_DET | L23_CLK_RMV_DIS | L1_CLK_RMV_DIS,
+ pcie->parf + PCIE20_PARF_SYS_CTRL);
+
+ writel(0, pcie->parf + PCIE20_PARF_Q2A_FLUSH);
+
+ dw_pcie_dbi_ro_wr_en(pci);
+ writel(PCIE_CAP_LINK1_VAL, pci->dbi_base + offset + PCI_EXP_SLTCAP);
+
+ /* Configure PCIe link capabilities for ASPM */
+ val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP);
+ val &= ~PCI_EXP_LNKCAP_ASPMS;
+ writel(val, pci->dbi_base + offset + PCI_EXP_LNKCAP);
+
+ writel(PCI_EXP_DEVCTL2_COMP_TMOUT_DIS, pci->dbi_base + offset +
+ PCI_EXP_DEVCTL2);
+
+ for (i = 0; i < 256; i++)
+ writel(0x0, pcie->parf + PCIE20_PARF_BDF_TO_SID_TABLE_N
+ + (4 * i));
+
+ return 0;
+}
+
static int qcom_pcie_link_up(struct dw_pcie *pci)
{
u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
@@ -1487,6 +1618,15 @@ static const struct qcom_pcie_ops ops_1_9_0 = {
.config_sid = qcom_pcie_config_sid_sm8250,
};

+/* Qcom IP rev.: 2.9.0 Synopsys IP rev.: 5.00a */
+static const struct qcom_pcie_ops ops_2_9_0 = {
+ .get_resources = qcom_pcie_get_resources_2_9_0,
+ .init = qcom_pcie_init_2_9_0,
+ .post_init = qcom_pcie_post_init_2_9_0,
+ .deinit = qcom_pcie_deinit_2_9_0,
+ .ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
+};
+
static const struct qcom_pcie_cfg apq8084_cfg = {
.ops = &ops_1_0_0,
};
@@ -1520,6 +1660,10 @@ static const struct qcom_pcie_cfg sc7280_cfg = {
.pipe_clk_need_muxing = true,
};

+static const struct qcom_pcie_cfg ipq6018_cfg = {
+ .ops = &ops_2_9_0,
+};
+
static const struct dw_pcie_ops dw_pcie_ops = {
.link_up = qcom_pcie_link_up,
.start_link = qcom_pcie_start_link,
@@ -1629,6 +1773,7 @@ static const struct of_device_id qcom_pcie_match[] = {
{ .compatible = "qcom,pcie-sm8250", .data = &sm8250_cfg },
{ .compatible = "qcom,pcie-sc8180x", .data = &sm8250_cfg },
{ .compatible = "qcom,pcie-sc7280", .data = &sc7280_cfg },
+ { .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg },
{ }
};

--
2.34.1